Article
Astronomy & Astrophysics
Takanori Sato, Fuminobu Takahashi, Masaki Yamada
Summary: This paper investigates the gravitational production of dark photon dark matter during inflation when dark photons acquire mass through the Higgs mechanism. The research reveals that the energy density spectrum of dark photons can have two peaks at intermediate and small scales. Dark photons can explain dark matter, but their current mass needs to fall within a specific range.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Mariana Carrillo Gonzalez, Qiuyue Liang, Jeremy Sakstein, Mark Trodden
Summary: The tension between measurements of the Hubble constant at different redshifts may indicate new physics at play in the early universe, potentially involving early dark energy and scalar field interactions with standard model neutrinos. A neutrino-assisted early dark energy model is proposed to explain the coincidence between different epochs, with detailed analysis and constraints needed for validation. This scenario opens up new avenues for testing using cosmological data sets.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Mar Bastero-Gil, Antonio Torres Manso
Summary: We present a supersymmetric extension of a unified model for inflation and Dark Matter, which is based on the incomplete decay of the inflaton field into right-handed neutrino pairs. By imposing a discrete interchange symmetry on the inflaton and right-handed neutrinos, stability of the inflaton field at the global minimum is ensured, while still allowing partial decay and reheating of the Universe. Compatibility with inflationary predictions, BBN bounds, and obtaining the right DM abundance typically requires large couplings to the neutrino sector.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Logan Morrison, Stefano Profumo, Dean J. Robinson
Summary: The study discusses a dark QCD sector as a minimal extension of the Standard Model, which includes Dark Matter candidates without the need for additional interactions with the visible sector. Under specific conditions, this dark sector can generate Dark Matter candidates.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Yann Mambrini, Keith A. Olive, Jiaming Zheng
Summary: Dark matter may only interact with the visible sector at high energy scales. During the period of reheating, the dominant process of dark matter production is through the decay products of the inflaton. This process dominates for low reheating temperatures and can produce the required density of dark matter.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Seyong Kim, M. Laine
Summary: Recently, there have been questions regarding how kinetic equilibrium is maintained when freeze-out dynamics is pushed to low temperatures in the context of the scalar singlet dark matter model with a mass of 60 GeV. Langevin simulations are used to address the non-equilibrium momentum distribution of non-relativistic particles in a cosmological background. These simulations suggest that kinetic equilibrium is a good approximation down to temperatures around 1 GeV for scalar singlet masses below 60 GeV, with deviations appearing as a red-tilted spectrum. This confirms that a slightly larger coupling than in equilibrium is needed to obtain the correct abundance, reducing the annihilation cross section.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2023)
Article
Astronomy & Astrophysics
Wasif Husain, Anthony W. Thomas
Summary: This study examines neutron star models with dark matter in the core, investigating properties of different types of dark matter particles and their interactions. Constraints on mass, radius, and tidal deformability are considered, along with the distribution of energy density inside the stars. The presence and behavior of fermionic dark matter throughout the star is particularly noted.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Alberto Salvio
Summary: The article investigates the general effective field theory describing the interactions of a massless dark photon with all Standard Model particles. The thermal production rate, cosmological yield, and contribution to the effective number of neutrinos of the dark photon are calculated. These predictions meet current observational bounds and will be tested in future measurements.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2023)
Article
Astronomy & Astrophysics
Mohammad Ali Gorji
Summary: This paper discusses how the seed of dark matter is generated from light spectator fields during inflation and explains how the energy density of these excited modes dominates the universe's energy density during the time of matter and radiation equality, playing the role of dark matter.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2023)
Article
Physics, Particles & Fields
Borna Salehian, Hong-Yi Zhang, Mustafa A. Amin, David Kaiser, Mohammad Hossein Namjoo
Summary: This paper systematically derives the SP equations and relativistic corrections from the nonlinear and fully relativistic KGE equations in an expanding universe, providing insights into deviations and applicability beyond the SP system. The method presented simplifies the analysis of scalar dark matter dynamics and accurately captures deviations from the SP system towards the full KGE case, particularly in calculating the mass-radius relationship of solitons.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Astronomy & Astrophysics
Stephon Alexander, Heliudson Bernardo, Michael W. Toomey
Summary: We propose a kinetically mixed dark sector model to resolve the tensions in the Hubble and S8 parameters. Our model, inspired by string theory, includes an axion and a dilaton. Unlike other axio-dilaton models, our theory incorporates kinetic mixing between the two fields, allowing efficient energy transfer and avoiding the need for fine-tuned potentials. This model also has implications for the growth of perturbations and the potential connection to dark energy.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2023)
Article
Astronomy & Astrophysics
Cem Eroncel, Geraldine Servant
Summary: We demonstrate the formation of very compact axion mini-clusters through the kinetic misalignment mechanism in axion-like-particle (ALP) dark matter models. These mini-clusters are denser than those formed through standard misalignment or large misalignment scenarios. Our analysis shows that adiabatic fluctuations play a significant role in the amplification of ALP fluctuations in the early universe, leading to larger final sizes in the kinetic misalignment mechanism. We compare the halo mass functions and spectra obtained from different misalignment scenarios and present the results in terms of the ALP mass and decay constant.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2023)
Article
Astronomy & Astrophysics
Sougata Ganguly, Sourov Roy, Ananya Tapadar
Summary: The lack of information before BBN allows for the presence of a new species 0 with a specific energy density redshift. This non-standard cosmological setup enables a larger coupling between the dark and visible sectors, even without thermal equilibrium. By considering the U(1)Lmu-LT 0 U(1)X gauge extension of the SM, different cosmological phases of the thermally decoupled dark sector are studied. It is shown that the dark matter relic density and muon (g - 2) anomaly can be reconciled within this scenario, satisfying various constraints.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2023)
Article
Astronomy & Astrophysics
Mansi Dhuria, Viraj Karambelkar, Vikram Rentala, Priyanka Sarmah
Summary: This work explores a novel mechanism for inducing a 21 cm absorption signal in the global cosmological signal, different from standard cosmology and excess gas cooling models. The model predicts a strong, broadband absorption signal extending from early cosmic dark ages to higher frequencies where star formation effects are expected. The absorption signal may measure only the spin temperature evolution in certain regions of parameter space, which could provide insights into the nature of dark matter interactions.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Luca Di Luzio, Belen Gavela, Pablo Quilez, Andreas Ringwald
Summary: This study suggests that dark matter can be explained by an axion that solves the strong CP problem, with a wide range of mass values. A novel misalignment mechanism known as trapped misalignment occurs, due to the unique temperature dependence of the Z(N) axion potential. Trapped misalignment is more general and may dynamically source the recently proposed kinetic misalignment mechanism.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Physics, Nuclear
Sen Yang, Cheng Liu, Tao Zhu, Li Zhao, Qiang Wu, Ke Yang, Mubasher Jamil
Summary: This study investigates the spherical accretion flow onto general parametrized spherically symmetric black hole spacetimes, analyzing the accretion process for various perfect fluids. The influences of additional parameters beyond the Schwarzschild black hole on flow behavior are studied in detail, as well as the accretion of the ideal photon gas and its correspondence with the photon sphere for general parameterized spherically symmetric black holes. Possible extensions of the analysis are also discussed.
Article
Physics, Particles & Fields
Javlon Rayimbaev, Ahmadjon Abdujabbarov, Mubasher Jamil, Wen-Biao Han
Summary: This study investigates the effects of Einstein-(Ether gravity on magnetized particles orbiting a black hole immersed in a magnetic field, exploring the impact of free parameters on particle trajectories, innermost stable circular orbits, and collision energy. The study also compares these effects with those of rotating Kerr black holes, finding similar behavior for certain values. Additionally, the cases where a static /Ether black hole can be described as a Schwarzschild black hole in modified gravity are analyzed with corresponding parameter values.
Article
Astronomy & Astrophysics
Sourabh Nampalliwar, Saurabh Kumar, Kimet Jusufi, Qiang Wu, Mubasher Jamil, Paolo Salucci
Summary: This paper investigates the impact of a dark matter spike on the vicinity of the black hole Sgr A* in the center of the Milky Way. The study examines the influence of dark matter density on the shadow radius and image of the black hole, concluding that the effect is weak for realistic densities but may become significant at higher densities near the black hole. However, simulations with radio interferometry, similar to an EHT array, suggest that detecting this effect in the near future is unlikely.
ASTROPHYSICAL JOURNAL
(2021)
Article
Physics, Particles & Fields
Javlon Rayimbaev, Sanjar Shaymatov, Mubasher Jamil
Summary: This paper investigates circular orbits around a black hole surrounded by dark matter, showing how dark matter impacts the existence of circular orbits and exploring its applications in fitting and explaining black hole parameters.
EUROPEAN PHYSICAL JOURNAL C
(2021)
Correction
Physics, Particles & Fields
Sanjar Shaymatov, Bobomurat Ahmedov, Mubasher Jamil
EUROPEAN PHYSICAL JOURNAL C
(2021)
Article
Physics, Mathematical
Kimet Jusufi, Mustapha Azreg-Ainou, Mubasher Jamil, Tao Zhu
Summary: This paper investigates the effects of the Generalized Uncertainty Principle (GUP) on the shadow and quasinormal modes (QNMs) of GUP-modified Kerr black holes. The study reveals that the GUP modification increases the curvature radius of the shadow and that it increases linearly with the GUP parameter. By using observational data and fitting techniques, the upper limits of the GUP parameter and the correction parameter in the modified black hole metric are determined.
INTERNATIONAL JOURNAL OF GEOMETRIC METHODS IN MODERN PHYSICS
(2022)
Article
Astronomy & Astrophysics
Kimet Jusufi, Mustapha Azreg-Ainou, Mubasher Jamil, Emmanuel N. Saridakis
Summary: Using observations of the central black hole and stars, we extract constraints on Barrow entropy, finding an upper bound less strong than the Big Bang Nucleosynthesis but significantly stronger than late-time cosmological constraints.
Article
Astronomy & Astrophysics
Javlon Rayimbaev, Bushra Majeed, Mubasher Jamil, Kimet Jusufi, Anzhong Wang
Summary: In this article, we investigate the particle dynamics around a Bardeen-Kiselev black hole, including its geometrical properties, the dynamics of test particles, and the relationship with rotating Kerr black hole.
PHYSICS OF THE DARK UNIVERSE
(2022)
Article
Astronomy & Astrophysics
Kimet Jusufi, Mustapha Azreg-Ainou, Mubasher Jamil, Qiang Wu
Summary: This paper focuses on the relationship between quasinormal modes (QNMs) and a rotating black hole shadow, using the example of a quantum deformed Kerr black hole. The study shows that, in the eikonal limit, the real part of QNMs is related to the Keplerian frequency for equatorial orbits. The paper also explores the typical shadow radius, computes the corresponding modes, and investigates the thermodynamical stability of the quantum deformed Kerr black hole, as well as other astrophysical applications.
Article
Astronomy & Astrophysics
Javlon Rayimbaev, Ahmadjon Abdujabbarov, Mubasher Jamil, Wen-Biao Han, Malika Khudoyberdieva
Summary: This paper discusses the motion of various types of charged, magnetized, and neutral test particles near static and spherically symmetric electrically charged black holes in the Einstein-/Ether gravitational theory. The effects of the free parameters in the theory on particle motion in curved spacetime are analyzed, focusing on the stability of circular and radially varying orbits for different types of particles. The behavior of charged particle motion around black holes with a uniform magnetic field is investigated, and values of the parameters c13 and c14 are proposed to model astrophysical black holes based on the spin of Kerr black holes.
MODERN PHYSICS LETTERS A
(2022)
Article
Physics, Nuclear
Farruh Atamurotov, Mubasher Jamil, Kimet Jusufi
Summary: In this study, the optical properties of a renormalization group improved Schwarzschild black hole in a plasma medium are investigated. The deflection angle of light in the weak gravity regime is computed for uniform and non-uniform plasma media, revealing the modifications caused by the plasma medium. The effects of plasma media play an important role in the optical appearance of black holes.
Article
Physics, Particles & Fields
Kimet Jusufi, Salvatore Capozziello, Sebastian Bahamonde, Mubasher Jamil
Summary: We use observational data to constrain a black hole solution of extended teleparallel gravity models based on the S2 star orbiting the Galactic Center. We construct the shadow images of the Sgr A* black hole and find that the shadow radius increases with the parameter alpha. The observables, such as the deflection angle and angular diameter, are close to the Schwarzschild case. However, the electromagnetic intensity observed in the shadow images is smaller compared to General Relativity (GR), indicating differences in the Born-Infeld f(T) gravity.
EUROPEAN PHYSICAL JOURNAL C
(2022)
Article
Physics, Particles & Fields
Kimet Jusufi, Saurabh Kumar, Mustapha Azreg-Ainou, Mubasher Jamil, Qiang Wu, Cosimo Bambi
Summary: In this study, we investigate the possibility of a wormhole as a candidate for the central object of Sgr A(star) and test this idea by constraining their geometry using the motion of S2 star and the reconstructed shadow images. We consider three wormhole models and find that they satisfy the flare out condition. We also explore the accretion of infalling gas model and study the accretion rate, electromagnetic radiation intensity, and shadow images.
EUROPEAN PHYSICAL JOURNAL C
(2022)
Article
Physics, Particles & Fields
Sanjar Shaymatov, Mubasher Jamil, Kimet Jusufi, Kazuharu Bamba
Summary: In this study, we investigate the dynamics of test particles around a magnetized Ernst black hole, taking into account its surrounding magnetic field. We find that the magnetic field has a significant impact on the radius of the innermost stable circular orbit (ISCO) and the epicyclic frequencies, especially for charged particles. By analyzing the astrophysical quasiperiodic oscillation (QPO) data of three microquasars, we determine the order of magnitude of the magnetic field.
EUROPEAN PHYSICAL JOURNAL C
(2022)
Article
Astronomy & Astrophysics
Farruh Atamurotov, Kimet Jusufi, Mubasher Jamil, Ahmadjon Abdujabbarov, Mustapha Azreg-Ainou
Summary: This paper investigates the influence of axion-plasmon on the optical properties of Schwarzschild black hole. It is found that the size of the black hole shadow decreases with increasing axion-plasmon coupling, indicating changes in gravitational deflection angle and other properties.